C#中的双向/双向字典？
C#中的双向/双向字典？
提问于 2012-06-10 12:16:13
我想通过以下方式在字典中存储单词：
我可以逐字获取代码：dict["SomeWord"] -> 123，逐字获取代码：dict[123] -> "SomeWord"
这是真的吗？当然，一种方法是使用两个字典：Dictionary<string,int>和Dictionary<int,string>，但是有没有其他方法呢？
回答 13
Stack Overflow用户
回答已采纳
发布于 2012-06-10 14:02:55
我写了几个快速的类，让你做你想做的事情。您可能需要使用更多特性对其进行扩展，但这是一个很好的起点。
代码的用法如下所示：
var map = new Map<int, string>();
map.Add(42, "Hello");
Console.WriteLine(map.Forward[42]);
// Outputs "Hello"
Console.WriteLine(map.Reverse["Hello"]);
//Outputs 42定义如下：
public class Map<T1, T2>
{
private Dictionary<T1, T2> _forward = new Dictionary<T1, T2>();
private Dictionary<T2, T1> _reverse = new Dictionary<T2, T1>();
public Map()
{
this.Forward = new Indexer<T1, T2>(_forward);
this.Reverse = new Indexer<T2, T1>(_reverse);
}
public class Indexer<T3, T4>
{
private Dictionary<T3, T4> _dictionary;
public Indexer(Dictionary<T3, T4> dictionary)
{
_dictionary = dictionary;
}
public T4 this[T3 index]
{
get { return _dictionary[index]; }
set { _dictionary[index] = value; }
}
}
public void Add(T1 t1, T2 t2)
{
_forward.Add(t1, t2);
_reverse.Add(t2, t1);
}
public Indexer<T1, T2> Forward { get; private set; }
public Indexer<T2, T1> Reverse { get; private set; }
}Stack Overflow用户
发布于 2018-05-17 16:50:06
遗憾的是，您需要两个字典，每个方向一个字典。但是，您可以使用LINQ轻松获得反向字典：
Dictionary<T1, T2> dict = new Dictionary<T1, T2>();
Dictionary<T2, T1> dictInverse = dict.ToDictionary((i) => i.Value, (i) => i.Key);Stack Overflow用户
发布于 2017-01-28 15:52:55
通过添加初始化和包含方法扩展了谜代码。
public class Map<T1, T2> : IEnumerable<KeyValuePair<T1, T2>>
{
private readonly Dictionary<T1, T2> _forward = new Dictionary<T1, T2>();
private readonly Dictionary<T2, T1> _reverse = new Dictionary<T2, T1>();
public Map()
{
Forward = new Indexer<T1, T2>(_forward);
Reverse = new Indexer<T2, T1>(_reverse);
}
public Indexer<T1, T2> Forward { get; private set; }
public Indexer<T2, T1> Reverse { get; private set; }
public void Add(T1 t1, T2 t2)
{
_forward.Add(t1, t2);
_reverse.Add(t2, t1);
}
public void Remove(T1 t1)
{
T2 revKey = Forward[t1];
_forward.Remove(t1);
_reverse.Remove(revKey);
}
public void Remove(T2 t2)
{
T1 forwardKey = Reverse[t2];
_reverse.Remove(t2);
_forward.Remove(forwardKey);
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
public IEnumerator<KeyValuePair<T1, T2>> GetEnumerator()
{
return _forward.GetEnumerator();
}
public class Indexer<T3, T4>
{
private readonly Dictionary<T3, T4> _dictionary;
public Indexer(Dictionary<T3, T4> dictionary)
{
_dictionary = dictionary;
}
public T4 this[T3 index]
{
get { return _dictionary[index]; }
set { _dictionary[index] = value; }
}
public bool Contains(T3 key)
{
return _dictionary.ContainsKey(key);
}
}
}这是一个用例，请检查有效的括号
public static class ValidParenthesisExt
{
private static readonly Map<char, char>
_parenthesis = new Map<char, char>
{
{'(', ')'},
{'{', '}'},
{'[', ']'}
};
public static bool IsValidParenthesis(this string input)
{
var stack = new Stack<char>();
foreach (var c in input)
{
if (_parenthesis.Forward.Contains(c))
stack.Push(c);
else
{
if (stack.Count == 0) return false;
if (_parenthesis.Reverse[c] != stack.Pop())
return false;
}
}
return stack.Count == 0;
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/10966331
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